Experimental observation of photonic-crystal emission near a photonic band edge

Abstract
A three-dimensional tungsten photonic crystal is realized with a photonic band edge at λ∼4 μm wavelength. Its thermal emission is suppressed in the band gap regime and, at the same time, exhibits sharp peaks near the band edge. It is further observed that energy conversion efficiency from one side of the sample reaches η∼40%. This finding is attributed to a complete metallic photonic band gap in the infrared (λ⩾6 μm) and the enhanced density of photon states near the band edge of our tungsten photonic crystal.